This application claims priority under 35 U.S.C. xc2xa7xc2xa7119 and/or 365 to JP2001-142519 filed in Japan on May 14, 2001; the entire content of which is hereby incorporated by reference.
1. Field of the Invention
This invention relates to a crutch which has a height adjustable grip. More specifically, this invention pertains to a crutch which requires no holes formed in the crutch body frame thereof for adjusting the grip height and is able to adjust the height of the grip simply.
2. Prior Art Description
There have been proposals for a crutch with a height adjustment system in which the user can adjust the grip to a height which will suit his or her physique. For example, JP-A 6-86795 and JP-A 2000-237253 disclose such systems, in which a grip is mounted slidably in the vertical direction along a pair of support pipes for constituting the crutch main body, and a desired grip height can be achieved by inserting pins at the side of the grip into one of holes of the support pipes.
As disclosed in these publications, the grip height adjustment systems of the prior art are basically constituted such that the support pipes of the crutch are formed with a plurality of height adjustment holes. This may degrade the strength of the crutch body, and especially the bending strength thereof. Further, since it is necessary to form the holes in the support pipes, the manufacturing process becomes more complex. In addition, since the grip is fixed on its both sides to the respective support pipes with pins, the both ends of the grip must be removed from and attached to the corresponding support pipes each time when the height of the grip is adjusted. Therefore the height adjustment operation is troublesome and complex.
A main object of this invention is to provide a crutch having a height adjustable grip, which eliminates the need to form height adjustment holes in the support frame of the crutch main body.
The other object of this invention is to provide a crutch in which the height of the grip can be adjusted simply.
In order to achieve the above and other objects and advantages, according to this invention, there is provided a crutch which comprises:
a pair of vertical support frames;
a grip:
a vertically movable slider for supporting the grip, which is mounted on the vertical support frames so that it is slidable along the vertical support frames; and
a slider support means for fixing the vertically movable slider at a prescribed height of the vertical support frames, wherein
the slider support means has a fixed vertical pipe fixed at its lower end to the vertical support frames, a movable vertical pipe having an upper end portion on which the vertically movable slider is mounted, a plurality of height adjustment holes at prescribed intervals along an axial direction of the fixed vertical pipe or the movable vertical pipe, and a fixing pin insertable into the height adjustment holes which is constantly pushed horizontally by a spring force, and wherein
the lower end portion of the movable vertical pipe is slidably inserted into the fixed vertical pipe from an upper end opening thereof, and wherein
the height adjustment holes are formed in an upper end portion of the fixed vertical pipe or a lower end portion of the movable vertical pipe, while the fixing pin is provided on the lower end portion of the movable vertical pipe or the upper end of the fixed vertical pipe.
Since the grip height adjustment holes are formed in the fixed vertical pipe or movable vertical pipe, there is no need to form pin holes in the vertical support frames of the crutch and therefore the strength of the crutch itself is not deteriorated. Furthermore, the manufacturing process of the vertical support frames is made simple.
Moreover, when adjusting the height of the grip, it is only necessary to manipulate only one pin which is provided on the movable vertical pipe or fixed vertical pipe. Therefore, compared to conventional crutches which require removal and reinsertion of the pins on both ends of the grip, adjustment is very simple.
In a preferred embodiment of this invention, the movable vertical pipe is mounted on the vertically movable slider so that it is rotatable on its axis within a prescribed angle range. With this configuration, if one of the vertical pipe having the fixing pin is rotated while adjusting the height of the grip, it is possible to offset the fixing pin away from the holes in the other vertical pipe, thus preventing it from entering the holes. When the movable vertical pipe is rotated back to its original position at a desired height for the required hole, the pin will automatically enter the hole, making grip height adjustment simple and convenient.
In this invention, it is possible to make the grip and the vertically movable slider as a single member.
In addition, it is preferable that the fixing pin has a conical shape and is slightly tapered toward a tip end thereof. The advantage of this is that there is substantially no gap between the pin and the hole, which ensures that the grip fits tightly and does not rattle.